Flexible midsole for shoe and shoe incorporating same

ABSTRACT

A shoe includes an upper, an outsole, and a midsole. The midsole can be constructed with a plurality of geometric protrusions formed in the upper surface of the midsole, the lower surface of the midsole, or both surfaces. In one embodiment, the protrusions can be substantially triangular in cross-section. A plurality of grooves can separate the protrusions from one another including a first set grooves extending in a longitudinal direction, a second set of grooves extending in a lateral direction, a third set of grooves extending at a positive angle relative to longitudinal direction and a fourth set of grooves extending at a negative angle relative to the longitudinal direction.

BACKGROUND

Athletic shoes can be used in variety of circumstances and for a variety of purposes. Depending on the intended use of a shoe, it can be constructed differently or include different components than other types of shoes.

Running shoes can be constructed for multiple types of running environments and types of running. Often, road running shoes are constructed for running on pavement and other surfaces that are generally flat. These types of running shoes tend to be lightweight and flexible. Additionally, they include insulation to cushion or stabilize feet during repetitive strides on hard, even surfaces.

Cross-training shoes are constructed for workouts that include both aerobic and anaerobic types of activities. The soles of these shoes are often configured to maintain more contact with the ground to provide stability.

Trail-running shoes are often constructed for off-road routes that are rugged where the runner may encounter various obstacles such as puddles, mud, rocks, roots, and so forth. These shoes conventionally include aggressive treads for improved traction and are fortified to add stability and support. Generally, the outsole of the shoe extends substantially beyond the edges of the shoe's upper to provide the additional stability.

Shoes of all types conventionally include a midsole that provides cushioning and absorbs shocks to the feet of the wearer. While conventional midsoles can provide some cushioning, they can also reduce flexibility of the shoe. In some midsoles, a honeycomb type matrix is formed, wherein hollowed out sections are surrounded by interconnected vertical walls. However, such embodiments do not always provide the desired flexibility to a shoe, particularly in terms of the in-plane flexibility of the midsole.

SUMMARY

In one embodiment, a midsole includes a body having an upper and a lower surface and a plurality of triangular protrusions formed in at least one of the upper surface and the lower surface.

The plurality of triangular protrusions can be separated from each other by a plurality of grooves.

The plurality of grooves can include a first set of grooves extending in a first direction extending generally longitudinally from a heel portion through a toe portion.

The plurality of grooves can include a second set of grooves extending in a second direction substantially orthogonal to the first direction.

The plurality of grooves can include at least a third set of grooves extending in a third direction that is non-orthogonal to the first direction.

The third direction can be at an angle of approximately 45° to the first direction.

The plurality of grooves can include a first set of grooves extending at a defined angle relative to a longitudinal direction that extends generally from a heel portion through a toe portion. In other examples, the sets of grooves can be concentric.

The plurality of grooves can include a second set of grooves extending in a direction that is substantially orthogonal to the first set of grooves.

The defined angle can be approximately 45°.

The grooves can extend a depth of approximately 3.5 millimeters or more into the body.

The body can be formed of a material comprising at least one of ethyl vinyl acetate and polyurethane.

In one embodiment, a shoe includes an upper, an outsole, and a midsole, a body having an upper and a lower surface, and a plurality of triangular protrusions, square shaped protrusions, circular shaped protrusions, asymmetric shaped protrusions, other types of protrusions, or combinations thereof formed in at least one of the upper surface and the lower surface.

The plurality of triangular protrusions can be separated from each other by a plurality of grooves.

The plurality of grooves can include a first set of grooves extending in a first direction extending generally longitudinally from a heel portion through a toe portion.

The plurality of grooves can include a second set of grooves extending in a second direction substantially orthogonal to the first direction.

The plurality of grooves can include at least a third set of grooves extending in a third direction that is non-orthogonal to the first direction.

The third direction can be at an angle of approximately 45° to the first direction.

The plurality of grooves can include a first set of grooves extending at a defined angle relative to a longitudinal direction that extends generally from a heel portion through a toe portion.

The plurality of grooves can include a second set of grooves extending in a direction that is substantially orthogonal to the first set of grooves.

In one embodiment, a shoe includes an upper, an outsole, and a midsole. The midsole includes a body having an upper and an outer surface; a plurality of triangular protrusions formed in at least one of the upper surface and the lower surface, and the plurality of triangular protrusions are separated from each other by a plurality of grooves. The plurality of grooves can include a first set of grooves extending in a first direction extending generally longitudinally from a heel portion through a toe portion, a second set of grooves extending in a second direction substantially orthogonal to the first direction, a third set of grooves extending in a third direction that is oriented at an angle of approximately 45° to the first direction, and a fourth set of grooves extending in a fourth direction that is substantially orthogonal to the third direction.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate various embodiments of the present apparatus and are a part of the specification. The illustrated embodiments are merely examples of the present apparatus and do not limit the scope thereof.

FIG. 1 illustrates a side view of an example of a shoe in accordance with the present disclosure.

FIG. 2 is a bottom view of an outsole of a shoe in accordance with the present disclosure.

FIG. 3 is a rear view of a sole of a shoe in accordance with the present disclosure.

FIG. 4 is a front view of a sole of a shoe in accordance with the present disclosure.

FIG. 5 is a side view of a sole of a shoe in accordance with the present disclosure.

FIG. 6 is a top view of a midsole of a shoe in accordance with an embodiment of the present disclosure.

FIG. 7 is a cross-sectional view of a portion of the sole shown in FIG. 2.

FIG. 8 is a cross-sectional view of another portion of the sole shown in FIG. 2.

FIG. 9 is a top view of a midsole of a shoe in accordance with another embodiment of the present disclosure.

FIG. 10 is a top view of a midsole of a shoe in accordance with a further embodiment of the present disclosure.

DETAILED DESCRIPTION

FIG. 1 depicts an example of a running shoe 100. In this example, the running shoe 100 includes a sole 102 and an upper 104 connected to the sole 102. The sole 102 and the upper 104 collectively form a foot cavity 106 that receives a foot of the user. The upper 104 includes a slit or an opening that enables the size of the foot cavity 106 to vary while the user inserts or removes their foot. A tongue is connected to the upper 104 near the end of the slit. The tongue fills the gap defined by the slit when the user is wearing the running shoe 100. Multiple eyelets 110 are formed in the upper 104 adjacent to the slit 108 through which a lace 112 passes in a desired lacing pattern. The lace 112 can be loosened to enable the foot cavity 106 to be expanded while a user inserts or removes their foot, and can be tightened when the running shoe 100 is worn by the user to secure the user's foot within the foot cavity 106 of the shoe 100.

The foot cavity 106 can include a sock liner that lines portions of the foot cavity 106. Also, the side walls of the foot cavity 106 can include other types of cushioning that reduce the jarring impacts when the user's shoe strikes the running surface and holds the upper snuggly against the user's feet throughout the running motion. In some cases, the cushioning lines the entire surface of the foot cavity's wall. In other examples, the cushioning lines just a subset of the foot cavity 106.

In the example depicted in FIG. 1, the running shoe's upper 104 is configured as a low top profile wherein the upper 104 terminates at or below the user's ankle. The low top profile provides the running shoe with a lower weight and provides the user additional movement.

Referring to FIG. 2, bottom view of the sole 102, specifically the outsole 120 of the shoe 100 depicted in FIG. 1 is illustrated according to one example. The outsole 120 includes a tread or pattern on its lowermost surface for engagement with a running surface. In the embodiment shown, the tread includes a generally zig-zag or herring-bone pattern of alternating ridges 122 and grooves 124. The pattern of ridges 122 and grooves 124 can be separated into sections or zones 126 by grooves 128 extending into the outsole 120. An elongated depression or concavity 130 can extend through a portion of the outsole 120 located between a heel portions and a toe portion of the outsole 120. The outsole 120 can additionally include a toe bumper or toe guard 132 providing some protection for the users toes as well as providing an ergonomic traction surface associated with a runner rolling up onto and pushing off of their toes while they run. Another elongated depression or concavity 134 can extend from the toe section of the outsole 120 toward, and even into, the toe guard 132. The outsole 120 includes further grooves or concavities 136. The various grooves and concavities 128, 130, 134, 136 are sized and located to provide traction between the outsole 120 with a running surface as well as provide both stability and flexibility for a runner's foot.

Referring to FIGS. 3-5, the sole 102 additionally includes a midsole 140 positioned above the outsole 120. The midsole 140 is configured to provide cushioning and shock absorption to the runner. In one embodiment, the midsole can be configured of ethyl vinyl acetate (EVA). The midsole 140 can be attached to the outsole 120 by means of an appropriate adhesive. In some examples, the sole includes a paint trench 125.

As seen in FIGS. 6-8, the midsole 140 includes a variety of geometric surface features formed in its upper surface 142 providing flexibility to the midsole 140 in virtually every direction within the plane of the midsole 140. The geometric surface features include a plurality of protruding triangles 150 separated by grooves (generally indicated by 151 in FIGS. 7 and 8), including a first set of grooves 152 running in the longitudinal direction of the midsole (i.e., a direction running from the heel portion 160 to the toe portion 162), a second set of grooves 154 running in the lateral direction (e.g., perpendicular to the longitudinal direction), a third set of grooves 156 running at a positive angle relative to the longitudinal direction (e.g., +45°) and a fourth set of grooves 158 running at a negative angle relative to the longitudinal direction (e.g., −45°). In some cases, at least some of the grooves (met-head grooves 127) overlap with the metatarsal bones of the user's foot when the user is wearing the shoe.

In other terms, the geometric features of the upper surface 142 of the midsole can be describe as square or diamond shaped protrusions that are separated from one another by the angled grooves 156 and 158, and that are also divided four individual components (e.g., triangles) by the longitudinal and lateral grooves 152 and 154. In one embodiment, the grooves can extend a depth of approximately 3.5 millimeters (mm) from the upper surface of the midsole 140.

The various grooves 152, 154, 156 and 158 provide increased flexibility to the midsole 140 in every direction within the plane of the midsole 140, while the triangular protrusions 150 maintain a desired level of stability.

The midsole 140 can additionally include an elongated depression or concavity 160 formed in the upper surface 142 of the midsole 140. The concavity 160 can be sized, shaped and located to align with the elongated concavity 130 formed in the outsole 120. The elongated cavities 130 and 164 can provide increased flexibility, including lateral flexibility, in the region extending between heel and the toes.

The midsole 140 includes an peripheral rim 162 having a generally constant width and having a generally smooth upper surface, lacking in any surface features such as described above. The peripheral rim 166 provides stability to the midsole.

Referring briefly to FIG. 9, a midsole 200 according to another embodiment is shown. The midsole 200 includes a variety of geometric surface features formed in its upper surface 202 providing flexibility to the midsole 200 in virtually every direction within the plane of the midsole 200. The geometric surface features include a plurality of protruding quadrants 204 (or sectors or quarter circles) separated by grooves, including a first set of grooves 206 running at a positive angle relative to the longitudinal direction (e.g., +45° relative to a longitudinal axis extending from the heel portion 220 through the toe portion 222) and a second set of grooves 208 running at a negative angle relative to the longitudinal direction (e.g., −45°).

The geometric surface features additionally include a plurality of protruding triangular sections 210 separated by grooves including a third set of grooves 212 running in the longitudinal direction of the midsole (i.e., a direction running from the heel portion 220 to the toe portion 222), a fourth set of grooves 214 running in the lateral direction (e.g., perpendicular to the longitudinal direction). The triangular protrusions 210 are organized in a set of four triangles centrally located relative to four adjacent groups of protruding quadrants 204. A plurality of nonlinear depressions or concavities 216 are formed between adjacent triangular protrusions 210 and protruding quadrants 204. The concavities 216 can be formed at the same depth as the various grooves 206, 208, 212 and 214.

The midsole 200 can additionally include an elongated depression or concavity 230 formed in the upper surface 202 of the midsole 200. The concavity 230 can be sized, shaped and located to align with the elongated concavity 130 formed in the outsole 120 to which the midsole is attached. The elongated cavities 130 and 230 can provide increased flexibility, including lateral flexibility, in the region extending between heel and the toes.

The midsole 200 also includes a peripheral rim 240 having a generally constant width and having a generally smooth upper surface, lacking in any surface features such as described above. The peripheral rim 240 provides stability to the midsole.

The geometric features of the upper surface 202 of the midsole 200 can be described providing positive and negative angled grooves 206 and 208, longitudinal grooves 212, lateral grooves 214, as well as the intermittent concavities 216, which provide increased flexibility to the midsole 200 in every direction within the plane of the midsole 200, while the various protrusions 204 and 210 maintain a desired level of stability. In one example, the increased stability may stability the midsole on a gluing surface when gluing portions of the shoe together.

Referring briefly to FIG. 10, a midsole 300 according to another embodiment is shown. The midsole 300 includes a variety of geometric surface features formed in its upper surface 302 providing flexibility to the midsole 300 in virtually every direction within the plane of the midsole 300. The geometric surface features include a plurality of square (or rectangular) protrusions 304 surrounded by a plurality of triangular protrusions 306 with one triangular adjacent each of their four sides of the square protrusion 304. Each triangular protrusion 306 is separated from adjacent triangular protrusions 306 by grooves, including a first set of grooves 308 running at a positive angle relative to the longitudinal direction (e.g., +45° relative to a longitudinal axis extending from the heel portion 320 through the toe portion 322) and a second set of grooves 310 running at a negative angle relative to the longitudinal direction (e.g., −45°).

The square protrusions 304 are separated from adjacent triangular protrusions 306 by grooves including a third set of grooves 312 running in the longitudinal direction of the midsole (i.e., a direction running from the heel portion 320 to the toe portion 322) and a fourth set of grooves 314 running in the lateral direction (e.g., perpendicular to the longitudinal direction).

The midsole 300 can additionally include an elongated depression or concavity 330 formed in the upper surface 302 of the midsole 300. The concavity 330 can be sized, shaped, and located to align with the elongated concavity 130 formed in the outsole 120 to which the midsole 300 is attached. The elongated cavities 130 and 330 can provide increased flexibility, including lateral flexibility, in the region extending between heel and the toes.

The midsole 300 also includes a peripheral rim 340 having a generally constant width and having a generally smooth upper surface, lacking in any surface features such as described above. The peripheral rim 340 provides stability to the midsole.

The geometric features of the upper surface 302 of the midsole 300 can be described providing positive and negative angled grooves 308 and 310, longitudinal grooves 312, and lateral grooves 314, which provide increased flexibility to the midsole 300 in every direction within the plane of the midsole 300, while the various protrusions 304 and 06 maintain a desired level of stability.

GENERAL DESCRIPTION

In general, the present disclosure provides a midsole, and a shoe (e.g., a running shoe) incorporating a midsole, that provides substantial flexibility in every direction while also providing stability, and shock absorption for a user's foot by providing geometric surface features in an upper surface, a lower surface, or in both the upper and lower surfaces. In some embodiments, the geometric surface features include a plurality of protrusions in the upper surface (and/or lower surface), separated by a plurality of grooves. The grooves can include longitudinal grooves, lateral grooves and angular grooves. The angular grooves can include grooves set at a positive angle relative to the longitudinal grooves and/or grooves set at a negative angle relative to the longitudinal grooves. In one embodiment, the angled grooves can be oriented at an angle of plus or minus 45° relative to the longitudinal grooves. In other embodiments, the grooves can be oriented at other angles such as plus or minus 30°, plus or minus 60°, or in combinations of, for example, plus 60° and minus 30°, or in a variety of other orientations relative to the longitudinal or lateral grooves. In one embodiment, the grooves can extend a depth into the surface of the midsole of approximately 3.5 mm. In other embodiments, the grooves can extend a greater or lesser depth. For example, in one embodiment, the grooves can extend a depth of approximately 1 mm or less. In other embodiments the grooves can extend a depth of approximately 7 mm or greater. In some examples, the grooves can extend all the way through the thickness of the material.

The protrusions can be formed to exhibit any desired geometry. In some embodiments, at least some of the protrusions can be formed to exhibit substantially triangular geometries. In other embodiments, at least some of the protrusions can be formed to exhibit a sector of a circle, such as a quarter circle (quadrant). In other embodiments, at least some of the protrusions can be formed to exhibit square or rectangular geometries. In some embodiments, the protrusions can be configured to exhibit a combination of different geometries. The protrusions can be arranged in a desired pattern.

In some examples, where the shoe has a non-zero drop, the midsole of the sole is located above the outsole. The midsole is made of a material that provides cushioning while also providing stability. In some embodiments, the total height of the midsole and outsole under the heel can be about 25 mm and the total height of the midsole and outsole under the toe box can be about 15 mm. The difference in sole thickness between the heel and toe box can reduce the strain on the user's Achilles tendon. This drop in the height of the sole from the heel to the toe box can affect how the user's foot strikes the ground. In some cases, the heel drop can range from 4 mm to 10 mm. In some embodiments, the midsole can exhibit a thickness of approximately 17 mm in its thickest area.

The midsole can be constructed of various materials to provide cushioning. In some cases, the midsole is made of ethyl vinyl acetate (EVA) or polyurethane. EVA is a copolymer of ethylene and vinyl acetate with microscopic air bubbles formed within the material making it lightweight while providing a good amount of cushioning. Polyurethane also has a microscopic air bubble structure like EVA but is generally firmer and more resistant to compression than EVA. The midsole can be formed by molding (e.g., injection molding) or other appropriate manufacturing processes, enabling the grooves and protrusions to formed during the molding process.

In some embodiments, the outsole can include a rubber compound with a high carbon content at the heel and in the toe box area. The outsole can be constructed with studs, ridges, or other tread structures to provide traction on slippery surfaces, such as wet grass or slick pavement. In some examples, the outsole can include transverse grooves in the toe box area so that the running shoe is more flexible in the toe box area when the user's weight is loaded against the ball of the user's foot while the heel is raised off of the ground. Generally, the wider the outsole, the greater stability the outsole provides the foot. Although, a wide outsole can also increase the weight of the shoe. In some examples, the running shoe can include an outsole that is just as wide or has a width that is less than 5.0 percent greater than width of other corresponding sections of the shoe (e.g., corresponding sections of the midsole or upper).

In one embodiment, the midsole can be bonded to the outsole by use of an appropriate adhesive material. In other embodiments, the midsole can be formed with the outsole in a co-molding or co-injection molding process. In some cases, a co-injection molding process can be used wherein the outsole is first injected into a mold as a “skin” material, followed by injection of the midsole into the mold as a “core” material. In some processes, the material for the skin and the material for the core can be injected into the mold simultaneously. Co-injection molding processes provide product strength and performance and are able to utilize a variety of materials for injection into the mold, including high-impact plastics. Co-molding the outsole with the midsole can allow the midsole and the outsole to be fitted more compactly together than would otherwise be the case if they were injection molded separately.

In some embodiments, the sole can further include an insole located above the midsole. The insole can be removable or bonded to the midsole. In some embodiments, additional components can be associated with the sole including, for example, a stone guard. In one embodiment, a stone guard, configured to mitigate potential penetration of rocks, roots or other objects into the runners foot, can be positioned between an insole and the midsole of a shoe.

A shoe in accordance with the present disclosure can further include an upper attached to the sole. In some embodiments, the upper can made of a combination of lightweight nylon to reduce the running shoe's weight. However, a variety of other materials can be used to form the upper. The upper of a running shoe can also incorporate a heel counter that is commonly stiffer than in other athletic shoes to help control excessive pronation or supination during running.

In some embodiments, the upper can be formed of waterproof fabric. This prevents water from entering the shoe through the upper. The tongue of the running shoe can also include a waterproof fabric. In some circumstances the waterproof fabric of the tongue has the same characteristics as the waterproof fabric incorporated into the upper. In some embodiments, the waterproof fabric can be located on the underside of the tongue and on the inside of the upper adjacent the foot cavity. In some embodiments, the waterproof fabric of the upper that is located on the outside of the upper. In some embodiments, the tongue can be connected to the upper along the tongue's edges with a gusset. The gusset can also be lined with the waterproof material. In some cases, the gusset's waterproof fabric is located on the inside surface that is adjacent to the foot cavity. In other examples, the gusset's waterproof fabric is located on the outside surface of the gusset.

In some cases, the waterproof fabric is small enough to exclude water particles that would come from the ambient environment such as water from rain, mud puddles, or other sources while enabling water to move from the inside of the shoe to the outside through a diffusive mechanism. The diffusive water transport mechanism allows some water to be removed from the inside of the running shoe or from the inside layers of the running shoe.

The waterproof fabric that forms the protective exterior also includes a second, convective water transport mechanism. The convective water transport mechanism is enabled due to the waterproof fabric being air permeable such that a small amount of air passes through the waterproof fabric. This additional air circulation accelerates the removal of water moisture inside the foot cavity or water moisture inside the upper's insulation in the inside layer. Convective mass transport works largely via advection or the transport of water through air motion. The convective mass transfer does not require sweat build up. The waterproof fabric can transport air out of the shoe when the user's foot is inserted into the shoe or not.

Any appropriate type of running shoe, trail-running shoe, or cross-training shoe can be used in accordance with the principles described herein. In one example, the shoe can include a low-top profile where the upper terminates just below the user's ankle. While a low-top upper can provide less lateral stability, the shoe is lighter. In other examples, the shoe includes a high-top profile. In this example, the running shoe includes an upper that extends over the user's ankle. Other types of shoes, including non-athletic shoes, can also incorporate the principles, features or aspects disclosed herein. 

What is claimed is:
 1. A midsole for use in a shoe, the midsole comprising: a body having an upper and a lower surface; a plurality of triangular protrusions formed in at least one of the upper surface and the lower surface.
 2. The midsole of claim 1, wherein the plurality of triangular protrusions are separated from each other by a plurality of grooves.
 3. The midsole of claim 2, wherein the plurality of grooves include a first set of grooves extending in a first direction extending generally longitudinally from a heel portion through a toe portion.
 4. The midsole of claim 3, wherein the plurality of grooves includes a second set of grooves extending in a second direction substantially orthogonal to the first direction.
 5. The midsole of claim 4, wherein the plurality of grooves includes at least a third set of grooves extending in a third direction that is non-orthogonal to the first direction.
 6. The midsole of claim 4, wherein the third direction is at an angle of approximately 45° to the first direction.
 7. The midsole of claim 2, wherein the plurality of grooves include a first set of grooves extending at a defined angle relative to a longitudinal direction that extends generally from a heel portion through a toe portion.
 8. The midsole of claim 7, wherein the plurality of grooves includes a second set of grooves extending in a direction that is substantially orthogonal to the first set of grooves.
 9. The midsole of claim 8, wherein the defined angle is approximately 45°.
 10. The midsole of claim 2, wherein the grooves extend a depth of approximately 3.5 millimeters into the body.
 11. The midsole of claim 2, wherein the body is formed of a material comprising at least one of ethyl vinyl acetate and polyurethane.
 12. A shoe, comprising: an upper; an outsole; and a midsole comprising: a body having an upper and a lower surface, a plurality of triangular protrusions formed in at least one of the upper surface and the lower surface.
 13. The shoe of claim 12, wherein the plurality of triangular protrusions are separated from each other by a plurality of grooves.
 14. The shoe of claim 13, wherein the plurality of grooves include a first set of grooves extending in a first direction extending generally longitudinally from a heel portion through a toe portion.
 15. The shoe of claim 14, wherein the plurality of grooves includes a second set of grooves extending in a second direction substantially orthogonal to the first direction.
 16. The shoe of claim 15, wherein the plurality of grooves includes at least a third set of grooves extending in a third direction that is non-orthogonal to the first direction.
 17. The shoe of claim 15, wherein the third direction is at an angle of approximately 45° to the first direction.
 18. The shoe of claim 13, wherein the plurality of grooves include a first set of grooves extending at a defined angle relative to a longitudinal direction that extends generally from a heel portion through a toe portion.
 19. The midsole of claim 18, wherein the plurality of grooves includes a second set of grooves extending in a direction that is substantially orthogonal to the first set of grooves.
 20. A shoe, comprising: an upper; an outsole; and a midsole comprising: a body having an upper and a lower surface, a plurality of triangular protrusions formed in at least one of the upper surface and the lower surface, the plurality of triangular protrusions are separated from each other by a plurality of grooves, the plurality of grooves including: a first set of grooves extending in a first direction extending generally longitudinally from a heel portion through a toe portion, a second set of grooves extending in a second direction substantially orthogonal to the first direction, a third set of grooves extending in a third direction that is oriented at an angle of approximately 45° to the first direction; and a fourth set of grooves extending in a fourth direction that is substantially orthogonal to the third direction. 